Over the years, emergency lifesaving and rescue craft have evolved from large cumbersome rigid lifeboat-like structures to a variety of types generically classified under the designation, liferafts. An early widely used design had a rigid, rectangularly shaped balsa flotation member with a webbing connecting opposite sides across the middle. These were hung or piled wherever there was space and, when a ship went down, they would float free. The few survivors who might clamber aboard would be at the mercy of the elements. From those who were not drowned as wind and waves repeatedly capsized or washed over the rafts, hypothermia took its toll. A family of inflatable rafts were developed primarily to reduce the space otherwise occupied by the rigid ones. Yet, since they were similar in design, lifeless or empty rafts often were all that search parties found.
One noteworthy attempt to provide a degree of protection against ice and cold weather was disclosed by Robert Bicknell et al., in U.S. Pat. No. 2,908,919. An inflatable liferaft was intended for colder climes so had two-ply insulative panels arranged to form a dome shaped chamber. Double walls, inflatable ribs and inflatable hatches were thought to provide a snug respite in stormy seas. As a matter of fact, the Bicknell et al., raft was thought to be such a cozy structure, it was intended to be a shelter upon its inhabitants' landfall. It even included a ballasted boarding ramp for ease of access and, along with a number of circumferentially disposed water ballast buckets, was said to be stable. Although the ballasting means were hoped to stabilize the liferaft in heavy sea states and severe winds, actual demonstrations raised doubts as to their ability to handle this problem. Furthermore, when the survivors were rescued at sea from a helicopter, they would have to jump into the sea to put on a rescue harness since it is nearly impossible to drop a rescue line through the hatchway of a bobbing raft. The cold water immersion in the wind further reduces a victim's possibility of survival. Added to this, the downwash from the helicopter increases the chances of hypothermia. Usually the victim's numbness prevents their donning the harness or renders them unconscious. Frequently, a rescue crewman must jump into the water and attach the harness, particularly with the incapacitated. Now, the crewman must be rescued with all the problems associated with such a hazardous exposure.
A somewhat similar design was patented by R. J. Phillips in U.S. Pat. No. 2,970,324. His liferaft had an inflatable central strut holding up a canopy and mounting a small shackle joined to a number of straps. Each of the straps is sewn to a load-spreading piece which reaches around and is secured to the extremity of the raft. A further set of straps coupled to load-spreading pieces on the raft floor was provided to distribute a load. This arrangement was to allow the launching of the inflated raft over the side of a ship or the like after being loaded with passengers. The small shackle mounted on the strut is suitable for interconnection to a ship's crane only by an attendant standing on a relatively stable surface. It is certainly not suited for engagement to an aircraft as the raft bobs on the ocean's surface. Additionally, this design appears to be vulnerable to the effects of wind and surface wave action. A later design is shown by Rex Smith in his "Inflatable Liferafts" of U.S. Pat. No. 3,222,700. He has a bridle cemented to the underside of a floor at spaced positions around the gunwale of his raft. An additional webbing bridle aids in the lowering of a loaded liferaft. Although it is purported that survivors can be hauled up to a deck by making an attachment with a shackle, its size, location and manner of attachment make such an operation nearly impossible in high sea and wind states by a surface craft, let alone a helicopter. Several peripherally disposed buoyancy chambers optimistically seek to resist the effects of wind and waves and inflatable members help shape the dimensions of a topless canopy.
A more recently developed inflatable liferaft includes lifesaving capabilities that mark it a major advance in lifesaving equipment for sea emergencies. It is known as the "Givens Buoy Raft" and is marketed by Res-Q-Raft, Inc. of Portsmouth, R.I. Simply stated, the raft combines several proven features for increasing the survivability of disaster victims. Its compact size and quick inflation time make it suitable for aircraft and other applications where space is at a premium. An inflatable double floor, double canopy and three arch tubes protect its occupants from exposure to wind and water. A hemispherical ballasting chamber self-fills with water so that the raft will not flip over in heavy winds or heavy seas nor will it overturn as survivors are crawling aboard. Recent approval by the United States Coast Guard further attests to its worth. However, like the preceding rafts, when the survivors are being rescued from the raft by a helicopter, they frequently must jump into the numbing water to put on a hoisting sling. Often times the victims are so fatigued and numbed from the exposure of the ordeal that they are incapable of fastening a hoisting sling about themselves. Those who are incapacitated by injury further complicate recovery. A helicopter crewman or swimmer must jump into the water and make the hoisting line attachment. The hundred knot plus helicopter downwash, icy waters and other winds can quickly bring on hypothermia for both the victim and the would be rescuer. During the time it takes for the lifting harness to be attached to a weakened victim, the victim to be retrieved and taken out of the harness, and the harness again to be lowered for the crewman and his recovery, a strong possibility exists that one if not both might become fatalities. The odds that some fatalities will occur increase dramatically as the number of survivors in the raft increases or if any are incapacitated. Irrespective of the fact that the raft's occupants have survived a disaster and a long withering exposure to the elements, it is a too often repeated tragedy that they perish when rescue seems so near at hand.
Thus, there is a continuing need in the state of the art for a liferaft affording a considerable degree of protection from the elements while being stable enough to withstand the effects of wind and wave action which facilitates the final stages of recovery by not needlessly subjecting the survivors to additional exposure.